If you really want a secure mobile just make your own. If you can't for patent and legal reasons, just make your own software. Just make sure the basics of security is integrated like encryption, pgp, ssl and all the other security crap everyone needs but Apple, Android don't have enough.
why the hell would you connect your house to the internet or any appliance on the Internet anyway. Getting your appliance to work on your computer or a computer so you can control it via 1 pc for various aspect is fine but connect it to the Internet and no matter how secure it is, someone will find a way in. Best security is to NOT connect it on your Internet. Hell pretty simple concept to understand
cause my ISP is a greedy mofo that charges me a high price if I go over a certain amount of bandwith. I've got my Internet service through a reseller so I pay around the same price but I know some resellers that are cheaper but they're 2 differences with resellers instead of the carrier directly 1- unlimited bandwith 2- support takes longer to solve problem if it gets complicated since they have to contact the carrier themselves. But in the end, i rather have a reseller ISP since I have unlimited bandwith so fuck you Bell or Videotron (Yup, I'm in Québec/Canada)